The following are ways to contact me, listed in order of my preference.
I always prefer face-to-face communication over any other medium. If we don't normally cross paths and you would like to meet with me, please coordinate a meeting over some other medium (e.g. e-mail).
I use the Freenode and OFTC IRC networks. My nick on both is "pehjota". You can find me in a channel or query me if you'd like. I generally reply within minutes or hours of contact. However, my IRC client runs 24 hours a day on this server. So even though I'm online, I may be asleep, travelling, or otherwise disconnected from my IRC client. I eventually receive all personal messages, so I should respond sometime within 24 hours.
The Simple Mail Transfer Protocol (SMTP) works very well for verbose asynchronous communication. You can reach me at <email@example.com>. Depending on the complexity of queries and my schedule, I usually reply to e-mail messages within a couple of hours or days.
You can also find me using the free and federated StatusNet microblogging software. My profile is at <http://identi.ca/pehjota>.
SMS/MMS and Voice
I have a mobile phone and use it to send and receive SMS ("text") messages, MMS ("picture") messages, and voice calls. I don't publish my phone number, but I may provide it on request.
I often find phone calls rather distracting, especially while working. I do submit, however, that they are useful and often time-saving for collaborative work, personal arrangements, and business communications.
My JID is <xmpp:PehJota@jabber.org>, but I rarely have my XMPP client running as few people contact me this way. If you'd like to talk to me over XMPP, you should first let me know via some other communication medium.